Apr
18
2009

Almost everything we'll need, right here: Almost.
Almost everything we'll need, right here: Almost.Courtesy Stefan Thlesen
BTW, Buzzketeers, if I ever catch you using the term “the john” when talking about a toilet, I will erase you from the story of my life. Sure, I just used it, but think I have the right to take possession of that word to divest it of its hurtfulness. Sort of like how ugly people are allowed to call stuff “fugly.”

Anyway, let’s consider the future of energy. We all know that we have to start conserving fossil fuels, so that we can use them with abandon in a dune buggy-filled Mad Max style future. (I like to think of this as “saving it for the party.”) In the mean time, we have to get clever. This week I noticed a couple of stories about people thinking outside the box with regards to energy. In one case, they’re thinking above the box, in the other they’re thinking below the box. (Or maybe they’re thinking in the box. It depends on what you use your boxes for.)

Check it out: a company called Solaren Corp has convinced the largest energy utility in California to purchase 200 megawatts of solar power from them by around 2016. The way they propose getting that power is the interesting thing—they plan on getting it from space.

Wait… that was poorly phrased. All solar power comes from space. What Solaren intends to do is launch a massive array of mirrors (as large as several miles across) into orbit to collect and reflect sunlight onto photoelectric cells. The cells will convert the sunlight into electric power, which will then be converted into radio waves and blasted down to a receiver on Earth. The radio energy will then be turned back into electricity. Solaren claims that the system could eventually generate 1.2 to 4.8 gigawatts of power at a price comparable to that of other alternative energy sources, enough to power 250,000 homes in California. And unlike land-based solar panels, the flow of energy wouldn’t depend on weather, and the orbit would be high enough that the system could provide energy 24 ours a day. They intend to launch it up to about 22,000 miles above the surface of the planet, meaning that it would be just inside of a high Earth orbit, and therefore geosynchronous. (I think.) Pretty neat, huh?

However, getting a couple miles of mirrors up to 22,000 miles above Earth is a little tricky. A little tricky, and super expensive. Building the receiving systems isn’t going to be cheap either. Some folks think that the project is altogether… unlikely. But the California power utility isn’t actually making an investment (i.e., taking a risk) they just promised to buy the power when it’s there (or if). But that commitment is probably comforting for investors.

Solaren says that the radio waves being sent back to Earth will be one sixth the intensity of sunlight. But what kind of radio waves are we talking about here? Visible light is composed of radio waves. So are radio, um, radio waves. Nope, we’re talking about microwaves. Microwaves have the advantage of being pretty high-energy. They have the disadvantage of being a little scary to me. And to other people. But it seems like it’s not all that dangerous; the center of the microwave beam would have an intensity of about 23 milliwatts per square centimeter. The limit for workplace exposure to microwaves in the US is 10 mw/cm2, so obviously 23 mw/cm2 is beyond what the government considers safe, but the area of maximum intensity is relatively small. Near the outside of the receiving array, the intensity would be closer to 1 mw/cm2. Birds flying through the center of the beam could have some trouble, and small aircraft and hot air balloons would do well to avoid it, but the metal shell of conventional planes should protect passengers entirely (the same way that your metal microwave protects you from the forces cooking your food). I suppose a super-villain could always hack into the satellite controls, and re-aim the system at a neighborhood. But that’s assuming that it ever gets built.

So from pie in the sky (a huge mirror pie), let’s turn our attention to fudge underground. It doesn’t have quite the sunshiny appeal of space mirrors, but it’s a little more feasible at the moment.

Remember how, in Mad Max 3: Beyond Thunderdome, Master Blaster was harvesting methane fuel from pig feces? Well, that works in the real world too, and not just with pig feces.

Consider the following: if you were to safe all of your… solid waste for one year, you could produce an amount of fuel equivalent to about 2.1 gallons of diesel fuel. I know—it doesn’t seem as much a it should, right? But if a city of 250,000 people was converting its waste into fuel, they’d have enough to drive 80 buses 62,000 miles each. If that figure sounds oddly specific, it’s only because that’s what Oslo, Norway intends to do. The city is all set to fuel its public transportation with brown gold. (Or with the biomethane produced by it.)

The cost of producing an amount of biomethane equivalent to a liter of diesel fuel comes to about 98 cents, while a liter of diesel costs about $1.30 at the pumps in Norway. And, unlike some other biofuels we won’t mention, it only gets into your food supply after you’ve eaten it.

Because the fuel comes from recently grown organic materials, it’s supposed to be carbon neutral, which is good. The article doesn’t say how energy intensive the process of making it is, though. Also, methane itself is a pretty bad greenhouse gas, but I suppose if it’s all burned efficiently that shouldn’t be a problem. (Burned methane makes CO2 and water.)

Energy may be plentiful in the future. We’ll just have to watch where we step.

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